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&GAS: ADD


item

Can be any of the following:

Item Explanation Unit
ATTACHMENT-COEFFICIENT Attachment coefficient/pressure 1/cm.Torr
DRIFT-VELOCITY Drift velocity cm/microsec
ION-DISSOCIATION Ion dissociation coefficient 1/cm.Torr
ION-MOBILITY Ion mobility cm2/microsec.V
LONGITUDINAL-DIFFUSION Longitudinal diffusion * sqrt(p) cm*sqrt(Torr) for 1 cm
LORENTZ-ANGLE Lorentz angle degrees
TOWNSEND-COEFFICIENT Townsend coefficient/pressure 1/cm.Torr
TRANSVERSE-DIFFUSION Transverse diffusion * sqrt(p) cm*sqrt(Torr) for 1 cm

Note that the same scalings have to be applied as for the TABLE.


function

The function may depend on the following variables:

Variable Meaning Unit
ANGLE_EB Angle between E and B degrees
ATTACHMENT Attachment coefficient / p 1/cm.Torr
B Magnetic field strength Tesla
BOLTZMANN Boltzmann constant 1.380658E-23 J/K
DISS Ion dissociation coefficient 1/cm.Torr
ECHARGE Electron charge 1.60217733E-19 C
EP Electric field / p V/cm.Torr
LORENTZ Lorentz angle degrees
MOBILITY Ion mobility cm2/microsec.V
P Pressure Torr
SIGMA_L Longitudinal diffusion * sqrt(p) cm*sqrt(Torr) for 1 cm
SIGMA_T Transverse diffusion * sqrt(p) cm*sqrt(Torr) for 1 cm
T Temperature K
TOWNSEND Townsend coefficient / p 1/cm.Torr
VELOCITY Electron drift velocity cm/microsec

The variable EP can always be used, ANGLE_EB and B can only be used in tables prepared for magnetic fields. The transport properties can be used only insofar as they have been entered already.


VS

If you wish to add experimental data to a table, you should prepare

The E/p vector should in principle cover the entire range of the table. If it doesn't, and if the selected item already exists, then values outside the range of the E/p vector are kept. If the E/p range is too short while the selected item doesn't yet exist, then the replacement is refused. No attempt is made to extrapolate the table.

The E/p values in your measurements do not have to coincide with the E/p values present in the table - your measurements will be interpolated at the values of the table and these interpolations are stored instead of the actual measurements.


order

Selects the degree of polynomial interpolation in the pair of vectors.

When the data is smooth, a value of 2 (quadratic interpolation) is a good choice. This may however lead to intermediate points with a negative value in for instance Townsend coefficient tables that usually start at 0. For such tables, linear interpolation is advised.

Instead of ORDER 1, you may also type LINEAR. QUADRATIC is a synonym for ORDER 2, CUBIC for ORDER 3.


Go to the top level, to &GAS, to ADD, to the topic index, to the table of contents, or to the full text.

Formatted on 0104-01-16 at 20:35.